TWI460160B - Adamantane derivative, manufacturing method thereof, and polymer using it as principal raw material and resin composition - Google Patents

Description

Adamantane derivative, its preparation method and polymer and resin composition thereof

The present invention relates to a functional resin composition, an adamantane derivative (an acrylate compound having an adamantane skeleton) using the polymer of the composition and a raw material thereof, and a method for producing the same, the optical property of the functional resin composition It is excellent in heat resistance and light transmittance, and can be used as a crosslinked resin, an optical fiber or an optical waveguide, an optical disk substrate, a KrF and ArF excimer laser, a F ₂ excimer laser photoresist, or an X-ray or an electron emission. Beams, EUVs (extreme ultraviolet light), optical materials such as chemically amplified photoresists, raw materials, pharmaceuticals, pesticide intermediates, and various other industrial products.

Since adamantane has a strong structure and high symmetry and exhibits excellent functions, it is known as a highly functional resin material, a pharmaceutical intermediate, an optical material (see Patent Documents 1 and 2), and particularly light. Resistance (refer to Patent Document 3) or the like is useful.

The resistive resin composition used in the semiconductor process must have a property of changing the irradiation portion to alkali solubility by light irradiation, etching resistance, substrate adhesion, transparency to a light source, and the like. When a light source is a short-wavelength light source after a KrF excimer laser, a chemically amplified photoresist is usually used, and the composition is usually used as a resin composition containing a main component, a photoacid generator, and a solution of several additives. . Among them, the main component, that is, the resin composition, is excellent in balance with various characteristics described above, and the photoresist performance is determined.

When a short-wavelength light source such as a KrF excimer laser is used as the light source, a chemically amplified photoresist is used. In this case, the resin composition of the main component is usually a polymer in which an acrylate or the like is a repeating unit. However, a single repeat unit is not used. When the reason is a single repeating unit, the characteristics such as etching resistance cannot be satisfied. Actually, a plurality of types of repeating units having functional groups for enhancing various characteristics, that is, two or more kinds of copolymers, are produced and formed into a resin composition. There is a proposal to disclose an acrylic resin (see Patent Documents 3 and 4) which uses a hydroxystyrene resin as a basic skeleton in the KrF excimer laser lithography resist, and in the case of an ArF excimer laser. 2-alkyl-2-adamantyl methacrylate is used as a basic skeleton.

However, in recent years, the miniaturization of the lithography process has progressed rapidly, and it is required to extend the life of each light source to a line width of about 1/3 of the wavelength. In particular, in the case of ArF excimer laser lithography, the above-described miniaturization is required by the application of the wetting technique or the introduction of the double patterning technique. At the same time, along with the thinning of the line width, the requirements for sensitivity or resolution, line edge roughness, etc. are becoming more and more strict.

In order to solve the problem, it has been studied to copolymerize the original resin with various acrylate compounds, or to greatly change the structure of the original resin. For example, there has been proposed a photoresist composition containing an adamantane derivative having a surface roughness or a line edge roughness at the time of etching (see Patent Document 5). However, in actuality, it is difficult to sufficiently satisfy the resolution at the time of thinning, the line edge roughness, and the like.

Prior technical literature Patent literature

Patent Document 1: Japanese Patent Publication No. 6-0305044

Patent Document 2: Special Fair No. 1-53633

Patent Document 3: Japanese Patent Publication No. 4-39665

Patent Document 4: Japanese Patent Publication No. Hei 10-319595

Patent Document 5: JP-A-2003-167346

Patent Document 6: JP-A-2000-122295

Patent Document 7: JP-A-2006-016379

Patent Document 8: JP-A-2000-136165

Non-patent literature

Non-Patent Document 1: SPIE, 6923-231 (2008)

From such a situation, it has been strongly demanded to develop an excellent functional resin composition which does not adversely affect the basic characteristics of the resin composition and which can achieve sensitivity or resolution and line edge roughness improvement. In particular, the content of the alcoholic hydroxyl group contained in the resin composition tends to have a feeling of improvement in sensitivity or resolution (see Non-Patent Document 1). As an example of the resin containing a monomer having an alcoholic hydroxyl group, for example, it is also proposed to disclose that the 3,5-dihydroxy-1-adamantyl (meth)acrylate contains two alcohol resins (see Patent Document 6). ), high sensitivity or high resolution as a photoresist performance is expected. Moreover, the monomer having acid dissociation contained in the photoresist polymer usually does not have an alcoholic hydroxyl group, and as a photoresist monomer having one alcoholic hydroxyl group and having acid dissociation properties, there is a proposal to disclose 3 -(1-Hydroxy-1-methylethyl)-1-(1-methylpropenyloxy-1-methylethyl)adamantane (Patent Document 7), as a high sensitivity of photoresist performance or High resolution is expected. Further, an acid-inductive compound (refer to the example of Patent Document 8) is disclosed, and it is disclosed as a composition for a photoresist which has a monocyclic or polycyclic ring which is substituted by an alcoholic hydroxyl group. Aliphatic ring.

An object of the present invention is to provide an adamantane derivative which has an adamantane skeleton and is useful as a cross-linking resin excellent in optical properties and the like, and a monomer used therein, and a process for producing the same.

Further, an object of the present invention is to provide a functional resin composition and a raw material compound (polymer) thereof as a KrF excimer laser, an ArF excimer laser, and an F ₂ excimer laser Or EUV is a chemically amplified type of photoresist that is induced by ultraviolet rays, and does not impair the pattern shape, dry etching resistance, heat resistance, etc. as the basic physical properties of the photoresist, and can achieve resolution or line edge roughness improvement, and Alkali imaging or substrate adhesion is excellent. The functional resin composition of the present invention is preferably a resin composition for a photoresist.

As a result of intensive studies on the above-mentioned problems, the present inventors have found that the acrylate compound derived from the adamantane structure represented by the formula (1) is expected to have an acid-dissociated tertiary ester group in the acid-dissociated adamantane skeleton. The acid dissociable group can also be easily removed in the case of alkali development, and is a compound suitable for the above purpose. Further, a polymer comprising a repeating unit represented by the formula (2), wherein the repeating unit represented by the formula (2) has an acrylate compound having an adamantane structure represented by the formula (1) as a raw material, and is expected to contain The functional resin composition of the polymer is useful as a photoresist system, and the present invention has been achieved.

(wherein R ₁ to R ₃ are the same or different and each represents a hydrogen atom, an alkyl group having 1 to 3 carbon atoms or an alkyl group containing a halogen; and R ₄ to R ₈ are the same or different and each represents a carbon number of 1 to 3; An alkyl group or a halogen-containing alkyl group, wherein X is the same or different, and is represented by a hydrogen atom, an alkyl group having 1 to 3 carbon atoms or an alkoxy group having 1 to 3 carbon atoms, and n is represented by 14)

(wherein R ₁ to R ₃ are the same or different and each represents a hydrogen atom, an alkyl group having 1 to 3 carbon atoms or an alkyl group containing a halogen; and R ₄ to R ₈ are the same or different and each represents a carbon number of 1 to 3; The alkyl group or the alkyl group containing a halogen, X is the same or different and is represented by a hydrogen atom, an alkyl group having 1 to 3 carbon atoms or an alkoxy group having 1 to 3 carbon atoms, and n is 14).

Further, an object of the present invention is to provide a method for producing an adamantane derivative represented by the above formula (1), which is represented by the adamantanol represented by the following formula (8) and represented by the following formula (9) or (10) Acrylic compound reaction:

(Wherein, R ₄ ~ R ₈ are the same or different system, it represents an alkyl group having a carbon number or an alkyl group having 1 to 3 of halogen, the same or different and X lines, represents a hydrogen atom, an alkyl group having 1 to 3 carbon atoms of , alkoxy group having 1 to 3 carbon atoms, n system means 14)

(R ₁ to R ₃ are the same or different and each represents a hydrogen atom, an alkyl group having 1 to 3 carbon atoms or an alkyl group containing a halogen, and Z is a hydroxyl group, an alkoxy group or a halogen group)

(Wherein the same or different, R ₁ ~ R ₃ lines, represents a hydrogen atom, an alkyl group having 1 to 3 carbon atoms of the alkyl group or a halogen-containing, halo-yl).

The adamantane derivative of the present invention is useful as an optical material such as a crosslinked resin, an optical fiber, an optical waveguide, an optical disk substrate, or a photoresist, a raw material thereof, a pharmaceutical, a pesticide intermediate, and various other industrial products. Further, the polymer and the functional resin composition of the present invention can be used as a KrF and ArF excimer laser, a F ₂ excimer laser photoresist material, or an X-ray, an electron beam, or an EUV (extreme ultraviolet light). Chemically amplified photoresist. The resin composition for a resist is excellent in etching resistance, and has excellent adhesion to a substrate and an alkali-soluble system. Needless to say, it is expected that a pattern having high sensitivity or high resolution can be formed with high precision.

Form of implementing the invention

First, an acrylate compound having an adamantane structure and a polymer and a functional resin composition using the same as the raw material of the present invention will be described.

The adamantane derivative represented by the formula (1) is obtained by using the adamantane represented by the formula (3) as a starting material. Examples of the compound represented by the formula (3) include 1,3-adamantanediol, 3-bromo-1-adamantanol, and 1,3-dibromoadamantane.

(In the formula, X is the same or different and represents a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, Y ₁ and Y ₂ representing a hydroxyl group or a halogen group, and n is a group of 14; The adamantane represented by the formula (3) is reacted with a carbon monoxide or a carbon monoxide source in the presence of a protonic acid to synthesize the adamantane dicarboxylic acid represented by the formula (4) at a high selectivity and yield.

Examples of the protic acid include organic acids (organic carboxylic acids such as formic acid, acetic acid, propionic acid, citric acid, oxalic acid, and tartaric acid, organic sulfonic acids such as methanesulfonic acid, benzenesulfonic acid, and p-toluenesulfonic acid, etc.), and inorganic acids. (eg hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, etc.). Among them, because of being inexpensive and easy to handle, it is preferred to use concentrated sulfuric acid.

The concentration of concentrated sulfuric acid used is preferably 90% by weight or more, more preferably 96% by weight or more. When the concentration is lower than this, the substituent (Y ₁ , Y ₂ ) is not sufficiently converted into a carboxylic acid group.

The amount of concentrated sulfuric acid used is preferably 2 to 20 times by weight, preferably 4 to 16 times by weight, more preferably 8 to 12 times by weight, based on the adamantane represented by the formula (3). Than it is large, the substituents (Y _1, Y ₂₎ is not sufficiently converted into a carboxylic acid group, and even more than that also yield multiple nor lifting.

The carbon monoxide used in the carboxylation reaction may be pure carbon monoxide or may be used by dilution with an inert gas. Carbon monoxide can be used at atmospheric pressure or under pressure using an autoclave.

The amount of carbon monoxide used may be selected from the range of 1 equivalent (in this case, when two carboxyl groups are introduced, 2 moles of carbon monoxide per 1 molar matrix) to 1000 equivalents, preferably 1 to 10 equivalents. More preferably, it is about 1 to 3 equivalents. When it is less, of course, the yield is lowered, and the yield is not changed more than its time. As the carbon monoxide source, formic acid or alkyl formate can also be used instead of carbon monoxide, and the amount used is the same at this time. When it is less, of course, the yield is lowered, and the yield is not increased more than it is.

Protonic acid can also be used as a solvent for the reaction of introducing a carboxyl group. Further, an inert organic solvent can also be used. Examples of the organic solvent include organic carboxylic acids such as acetic acid, nitriles such as acetonitrile and benzonitrile, and decylamines such as formamide, acetamide, dimethylformamide, and dimethylacetamide. Aliphatic hydrocarbons such as hexane, octane, etc., halogenated hydrocarbons, nitro compounds, tetrahydrofuran, diethyl ether, diisopropyl ether, two An ether such as an alkane, a mixed solvent thereof, or the like.

The above carboxylation reaction can be carried out smoothly even under mild conditions. The reaction temperature is, for example, -78 to 200 ° C, preferably about -20 to 100 ° C, and usually is usually about 0 to 80 ° C. At a lower temperature than this, the reaction does not proceed sufficiently, and at a higher temperature, the side reaction proceeds to lower the yield. The reaction can be carried out under normal pressure or under pressure.

The reaction time is usually from 1 to 100 hours, preferably from 1 to 10 hours. When it is shorter than this, the carboxylation reaction does not proceed sufficiently, and when it is longer than this, the yield does not change.

After completion of the reaction, the adamantane dicarboxylic acid represented by the formula (4) can be obtained by mixing the reaction solution with water or an aqueous alkaline solution. Further, after mixing with the alkaline aqueous solution, it is necessary to make the solution acidic again.

In the above method, it is preferred to use 1,3-adamantanediol as the adamantane, concentrated sulfuric acid as the protonic acid, and formic acid as the carbon monoxide source, which is simple and can be treated by a mild liquid phase reaction. The adamantane dicarboxylic acid represented by the formula (4) can be obtained with a high selectivity and a high yield.

Subsequently, the adamantane dicarboxylic acid represented by the formula (4) is alkylated to synthesize the adamantane dicarboxylate represented by the formula (5).

(In the formula, X is the same or different and represents a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, and R ₉ and R ₁₀ are each an alkyl group having 1 to 6 carbon atoms; n is a 14) alkyl esterification system, and the adamantane dicarboxylic acid represented by the formula (4) can be temporarily taken out, and then reacted with a corresponding alcohol under a protonic acid catalyst, and the adamantane represented by the formula (3) can also be used. After reacting with a protonic acid/carbon monoxide or carbon monoxide source, the corresponding alcohol is directly added to react. Examples of the alcohol to be used include methanol, ethanol, propanol, butanol, pentanol, hexanol, and cyclohexanol. The reaction is completed at a reaction temperature of 0 to 150 ° C and a reaction time of 1 to 5 hours. After completion of the reaction, it can be extracted with an organic solvent and washed with an alkali such as water or an aqueous sodium hydroxide solution, and then obtained by a known method such as concentration or recrystallization or column chromatography.

Examples of the organic solvent that can be used in the reaction or extraction include benzene, toluene, and xylene. , aromatic compounds such as cumene, ethylbenzene, 1,2,4-trimethylbenzene (pseudocumene), methyl acetate, ethyl acetate, propyl acetate, butyl acetate, amyl acetate, hexyl acetate, formic acid Methyl ester, ethyl formate, propyl formate, butyl formate, amyl formate, hexyl formate, methyl propionate, ethyl propionate, propyl propionate, butyl propionate, amyl propionate, propionic acid An ester of hexyl ester or the like, an alcohol compound such as butanol, pentanol, hexanol, heptanol or octanol, tetrahydrofuran, diethyl ether, diisopropyl ether, methyl-tert-butyl ether, two An ether compound such as an alkane.

Subsequently, the adamantane monocarboxylate represented by the formula (6) is synthesized by reacting the adamantane dicarboxylate represented by the formula (5) with an organometallic compound.

(wherein R ₄ and R ₅ are the same or different, and are represented by an alkyl group having 1 to 3 carbon atoms or an alkyl group containing a halogen; and R ₉ is an alkyl group having 1 to 6 carbon atoms, and X is the same or different It is represented by a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, and n is 14).

As the organometallic compound, the corresponding alkyllithium or alkylmagnesium halide can be used. Further, it is also possible to replace the organometallic compound by a Barbier reaction (hereinafter, collectively referred to as an organometallic compound) which directly reacts a mixture of a halogenated alkyl group/lithium metal or a halogenated alkyl/magnesium metal. .

The organometallic compound is preferably used in an amount of from 0.5 to 1 equivalent (1 equivalent is 3 times mole relative to 1 mole of raw material). When the amount used is less than the above, the reaction does not proceed sufficiently, and when the reaction proceeds to the diol, the yield is lowered. The solvent which can be used is not particularly specified if it is inert to the reaction. Can utilize tetrahydrofuran, diethyl ether, diisopropyl ether, methyl-tert-butyl ether, two An ether such as an alkane, an aliphatic hydrocarbon such as hexane, heptane, octane, decane, decane or cyclohexane, or benzene, toluene, xylene, trialkylbenzene, ethylbenzene or cumene. Aromatic compound.

The method of mixing the organometallic compound with the adamantane dicarboxylate represented by the formula (5) is not particularly limited. The organometallic compound may be dissolved in a solvent in advance, and the raw material dissolved in the solvent may be added dropwise thereto; and conversely, the raw material may be dissolved in a solvent in advance, and the organometallic compound diluted with a solvent may be added dropwise thereto. . However, it is preferable to heat up during mixing to avoid abnormal heating. The temperature at the time of mixing is preferably from 0 to 100 °C.

After mixing, it is preferred to cause the reaction to proceed at a reaction temperature of 0 to 100 °C. After the completion of the reaction, the reaction is stopped with water or alcohol, and then the adamantane monocarboxylic acid ester represented by the formula (6) can be obtained by a known method such as extraction, concentration, recrystallization, or column chromatography.

Subsequently, the adamantane alcohol represented by the formula (8) is synthesized by subjecting the adamantane monocarboxylic acid ester represented by the formula (6) to a transesterification reaction using an alcohol represented by the formula (7).

(wherein R ₆ to R ₈ are the same or different and each represents an alkyl group having 1 to 3 carbon atoms or an alkyl group containing a halogen, and M represents a hydrogen atom or an alkali metal)

(wherein R ₄ to R ₈ are the same or different and each represents an alkyl group having 1 to 3 carbon atoms or an alkyl group containing a halogen, and X is the same or different and represents a hydrogen atom and an alkyl group having 1 to 3 carbon atoms; And an alkoxy group having 1 to 3 carbon atoms, and n is 14). The alcohol represented by the formula (7) is 0.5 to 100 moles relative to the adamantane monocarboxylate represented by the formula (6), and preferably 3 to 20 moles per mole. Further, as the reaction solvent, tetrahydrofuran, diethyl ether, diisopropyl ether, methyl-tert-butyl ether, or the like can be used. An ether such as an alkane, an aliphatic hydrocarbon such as hexane, heptane, octane, decane, decane or cyclohexane, or benzene, toluene, xylene, trialkylbenzene, ethylbenzene or cumene. Aromatic compound.

The reaction system is usually carried out under basic or neutral conditions. When it is carried out under alkaline conditions, an alkali metal, a hydride thereof, an alkoxide or the like can be added. Further, when it is carried out under neutral conditions, a titanium alkoxide or the like can be added. The reaction temperature is, for example, 20 to 200 ° C, preferably about 50 to 150 ° C, and the reaction can be carried out while distilling off the produced alcohol.

Subsequently, the adamantyl alcohol represented by the formula (8) and the (meth)acrylic acid or a derivative thereof (hereinafter, an acrylic compound) are subjected to an esterification reaction to obtain a phase-target compound.

The adamantyl alcohol represented by the formula (8) can be used as it is, or can be substituted with an alkali metal such as lithium or sodium or a magnesium halide. Further, the esterification reaction with the acrylic compound represented by the formula (9) or the formula (10) can be carried out in accordance with a usual method using an acid catalyst or an alkali catalyst or a transesterification catalyst.

(R ₁ to R ₃ are the same or different and each represents a hydrogen atom, an alkyl group having 1 to 3 carbon atoms or an alkyl group containing a halogen, and Z is a hydroxyl group, an alkoxy group or a halogen group)

(R ₁ to R ₃ are the same or different and each represents a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, a halogen group, or a halogen-containing alkyl group).

Specific examples of the acrylic compound include acid compounds such as acrylic acid, methacrylic acid, 2-fluoroacrylic acid, trifluoroacrylic acid, and 2-(trifluoromethyl)acrylic acid, acrylonitrile chloride, methacrylic acid chloride, and the like. Acetyl hydrazine chloride, methyl acrylate, ethyl acrylate, tert-butyl acrylate, methyl methacrylate such as 2-fluoropropene fluorene chloride, trifluoropropene fluorene chloride, 2-(trifluoromethyl) propylene fluorene chloride Ethyl methacrylate, butyl methacrylate, methyl trifluoroacrylate, ethyl trifluoroacrylate, isopropyl trifluoroacrylate, tert-butyl trifluoroacrylate, methyl pentafluoromethyl methacrylate, Ethyl pentafluoromethacrylate, isopropyl pentafluoromethacrylate, tert-butyl pentafluoromethacrylate, methyl 2-fluoroacrylate, ethyl 2-fluoroacrylate, isopropyl 2-fluoroacrylate, 2 - tert-butyl fluoroacrylate, methyl 2-(trifluoromethyl)acrylate, ethyl 2-(trifluoromethyl)acrylate, or isopropyl 2-(trifluoromethyl)acrylate, 2-( Acrylates such as tributylmethyl)acrylic acid tributyl acrylate, sodium acrylate, sodium methacrylate, sodium 2-fluoroacrylate, trifluoro Acrylates such as sodium olefin and sodium 2-(trifluoromethyl)acrylate, acrylic anhydride, methacrylic anhydride, perfluoroacrylic anhydride, perfluoromethacrylic anhydride, 2,2'-difluoroacrylic anhydride, An acrylic anhydride such as 2-fluoroacrylic anhydride or 2-trifluoromethylacrylic anhydride. The amount used is 1 to 100 equivalents based on the raw material, preferably 1 to 10 equivalents, and the yield is lowered when it is less, which is uneconomical.

In order to allow the adamantanol represented by the formula (8) to react rapidly with the acrylic compound in a high yield, it is preferred to have an additive. When a mercapto halide or an acrylic anhydride is used as the acrylic compound, it is preferred to use an alkali compound as an additive. In other words, when a mercapto halide or an acrylic anhydride represented by acrylonitrile, methacrylic acid, methacrylic acid anhydride or methacrylic anhydride is used as the acrylic acid compound, the reaction system is rapidly formed when it is allowed to coexist with the alkali compound. The target substance can be obtained in a high yield. The alkali compound may, for example, be an organic base, and examples thereof include methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, n-propylamine, di-n-propylamine, diisopropylamine, and tri-n-propylamine. N-butylamine, di-n-butylamine, diisobutylamine, tri-n-butylamine, diphenylamine, 1,5-diazabicyclo[4.3.0]nonene-5, 1,5-diazabicyclo[5.4 .0] an amine such as undecene-5, diazabicyclo[2.2.2]octane or the like, and an organic amine such as aniline, methylaniline, dimethylaniline, toluidine, anisidine, chlorine Nitrogen-containing heterocyclic compounds such as anilines such as aniline, bromoaniline, nitroaniline and aminobenzoic acid, pyridines such as pyridine and dimethylaminopyridine, azoles, quinolines and piperidines. Metal alkoxides such as sodium methoxide or lithium methoxide, tetraammonium hydroxide, trimethylammonium hydride or tetraammonium hydroxide, amines such as ammonium sulphate, trimethylammonium nitrate or benzyl ammonium chloride A Grignard reagent such as an inorganic base such as a sulfate, a nitrate, a chloride or the like, sodium hydrogencarbonate or the like, or ethylmagnesium bromide may be present in the reaction solution.

The amount of these additives to be used is preferably 10 equivalents or less based on the raw material. There is no added effect when it is more than that. The method of adding the alkali compound is not particularly limited. It may be added before the addition of the acrylic compound, or may be added after the addition of the acrylic compound, or may be added simultaneously with the addition of the acrylic compound. In this case, when the reaction temperature is controlled so as not to abnormally increase the temperature, it is preferable because the progress of the side reaction can be suppressed. As the solvent, it is preferred that the solubility of the raw material and the target substance is high. Examples of such a compound include halogen compounds such as dichloromethane, chloroform and 1,2-dichloroethane, and tetrahydrofuran and An ether compound such as an alkane, diethyl ether, propyl ether or methyl-tert-butyl ether; an aliphatic hydrocarbon having 6 to 10 carbon atoms such as hexane, heptane, octane, decane or decane; An alicyclic hydrocarbon having 6 to 10 carbon atoms such as hexane, methylcyclohexane, dimethylcyclohexane or ethylcyclohexane, benzene, toluene, xylene, trialkylbenzene, ethylbenzene or isopropyl An aromatic hydrocarbon such as benzene. The reaction temperature is -70 to 200 ° C, preferably -50 to 80 ° C. When the temperature is lower than -70 ° C, the reaction rate is lowered, and when it is higher than 200 ° C, it is difficult to control the reaction or the side reaction is caused to cause a decrease in the yield.

When an acrylic compound represented by acrylic acid or methacrylic acid is used as the acrylic compound, a method of removing by-produced water in the reaction by using an acid catalyst and azeotropic or dehydrating agent is preferred. The Dean-Stark water separator can be used by azeotropic removal of water. As the acid catalyst, the inorganic acid is sulfuric acid or the like, and the organic acid is preferably benzenesulfonic acid or p-toluenesulfonic acid. As the dehydrating agent, well-known materials can be used, but concentrated sulfuric acid, boron trifluoride diethyl ether, trifluoroacetic anhydride, dicyclohexylcarbodiimide, 2-halobenzothiazolium fluoroborate, 2-halogenation Pyridinium salt, triphenylphosphine, thionyl chloride/halide or the like is preferred.

When the water to be produced is removed by azeotropic removal as a solvent, a solvent which is low in compatibility with water, has high solubility in a target substance, and is inert to the reaction of the present invention is selected. Further, in order to remove water which is by-produced in the reaction, it is preferred to use a solvent which azeotropes with water. Examples of such an organic solvent include aliphatic hydrocarbons having 6 to 10 carbon atoms such as hexane, heptane, octane, decane, and decane, cyclohexane, methylcyclohexane, and dimethylcyclohexane. An aromatic compound such as an alicyclic hydrocarbon having 6 to 10 carbon atoms such as hexane or ethylcyclohexane, or a benzene, toluene, xylene, ethylbenzene, cumene or trialkylbenzene. When a dehydrating agent is used, a nitrile such as acetonitrile or benzonitrile, a decylamine such as formamide, acetamide, dimethylformamide or dimethylacetamide, hexane or heptane may be mentioned. An aliphatic hydrocarbon having 6 to 10 carbon atoms such as octane, decane or decane, or a carbon number of 6 to 10 such as cyclohexane, methylcyclohexane, dimethylcyclohexane or ethylcyclohexane. Cycloesters, halogenated hydrocarbons, nitro compounds, esters of ethyl acetate, etc., tetrahydrofuran, diethyl ether, diisopropyl ether, two An ether such as an alkane. These solvents may be used alone or in combination of two or more kinds of solvents. The solvent is preferably used in an amount of 0.1 to 20 parts by weight based on 1 part by weight of the raw material, and is preferably used in an amount of 1 to 10 parts by weight. At the reaction temperature of the present invention, azeotropic dehydration is the azeotropic temperature of the organic solvent used with water. The use of the dehydrating agent is not limited to this. When the reaction temperature is lower than 60 ° C, the reaction rate is remarkably lowered, and when it is higher than 150 ° C, the selectivity of the target substance is lowered.

When an acrylate such as methyl acrylate or methyl methacrylate is used as the acrylic acid compound, the corresponding alcohol can be removed by a known method such as distillation (ethanol in the case of methoxy group and ethanol in the case of ethoxy group) to obtain a target. substance. Examples of the metal or a derivative thereof to be added as a catalyst include metals such as tin, titanium, lanthanum, zinc, lead, cobalt, iron, zirconium, manganese, lanthanum, potassium, and the like. As the derivative, a halogen compound, an oxide, a carbonate, a metal alkoxide, a carboxylate or the like is preferred. The reaction temperature is 0 to 200 ° C, more preferably 50 to 150 ° C. When the temperature is lower than 0 ° C, the reaction time is lowered, and when it is higher than 200 ° C, the side reaction proceeds to lower the yield. When the corresponding alcohol is removed outside the reaction system by distillation, a method of reacting in the vicinity of the boiling point of the corresponding alcohol may be mentioned. As the solvent, it is preferred that the raw material and the target substance have high solubility and are inert to the reaction. Such a halogen compound such as dichloromethane, chloroform or 1,2-dichloroethane; an ether compound such as tetrahydrofuran, diethyl ether or methyl-tert-butyl ether; benzene, toluene or hexane; A hydrocarbon compound such as heptane or a nitrile compound such as acetonitrile.

Further, the hydroxyl group of the diol derivative having an alicyclic structure may be an alkali metal such as lithium or sodium, an alkyl lithium such as butyl lithium or a Grignard reagent such as ethyl magnesium bromide. After the alcoholate state is obtained, the esterification reaction is carried out. In other words, the hydroxy group, that is, the OH group, may be converted into an OX group (X-based Li, Na, MgBr, MgCl, etc.) and then subjected to an esterification reaction. The reaction time of the esterification reaction of the present invention must be 0.5 to 100 hours, preferably 1 to 10 hours. The reaction time depends on the reaction temperature, the method of the esterification reaction, and the like, and is determined according to the desired yield and the like, and is not limited to the above range.

A polymerization inhibitor may also be added during the esterification process. The polymerization inhibitor is not particularly limited as long as it is a usual one, and 2,2,6,6-tetramethyl-4-hydroxypiperidine-1-oxo, N-nitrosophenylhydroxylamine ammonium salt, N-nitrosophenylhydroxylamine aluminum salt, N-nitroso-N-(1-naphthyl)hydroxylamine ammonium salt, N-nitrosodiphenylamine, N-nitroso-N-methylaniline, sub Nitro-naphthol, p-nitrosophenol, nitroso compound such as N,N'-dimethyl-p-nitroanilide, thiophene a sulfur-containing compound such as methylene blue or 2-hydrothiobenzimidazole, N,N'-diphenyl-p-phenylenediamine, N-phenyl-N'-isopropyl-p-phenylenediamine, An amine such as 4-hydroxydiphenylamine or aminophenol, an oxime such as hydroxyquinoline, hydroquinone, methylhydroquinone, p-benzoquinone or hydroquinone monomethyl ether, methoxyphenol, 2,4- Dimethyl-6-tert-butylphenol, catechol, 3-t-butylcatechol, 2,2-methylenebis-(6-t-butyl-4-methylphenol), etc. Examples include phenols, quinones such as N-hydroxy quinone, hydrazines such as cyclohexane hydrazine and p-benzoquinone, and dialkyl thiodipropionates. The amount added is preferably 0.001 to 10% by weight based on the acrylic compound, and preferably 0.01 to 1% by weight.

After completion of the reaction, the reaction solution is washed with water to remove excess acrylate compound and an additive such as an acid or a base. In this case, the washing water may contain an appropriate inorganic salt such as sodium chloride or sodium hydrogencarbonate. Further, the unreacted acrylic compound was removed by alkali washing. The alkali washing may be an aqueous sodium hydroxide solution, a potassium hydroxide aqueous solution, an aqueous sodium carbonate solution, an aqueous sodium hydrogencarbonate solution, or an aqueous ammonia solution. However, the alkali component to be used is not particularly limited, and may be acid-washed in order to remove metal impurities. net. Examples of the acid washing include an organic acid such as a hydrochloric acid aqueous solution, a sulfuric acid aqueous solution, or a phosphoric acid aqueous solution, and an organic acid such as an aqueous oxalic acid solution. In addition, in the case of washing, the organic solvent may be added to the reaction liquid in accordance with the physical properties of the compound represented by the formula (8) or the product represented by the formula (1). The organic solvent to be added may be the same as or the same as the reaction, and it is usually preferred to use a solvent having a small polarity which is well separated from water.

In the present invention, each reaction process can be carried out under normal pressure, reduced pressure or under pressure. Further, the reaction can be carried out by a usual method such as batch type, semi-batch type, or continuous type. In each process, the respective derivatives can be isolated, and can also be directly used in the next process in a non-segregated state. After the completion of the reaction, the separation means can be easily separated and purified by a usual method such as filtration, concentration, distillation, extraction, crystallization, recrystallization, column chromatography, separation by means of activated carbon purification or the like. .

The polymer of the present invention contains a polymer of a repeating unit represented by the following formula (2), and can be produced by using the adamantane derivative thus obtained as a repeating unit and homopolymerizing or copolymerizing.

(wherein R ₁ to R ₃ are the same or different and each represents a hydrogen atom, an alkyl group having 1 to 3 carbon atoms or an alkyl group containing a halogen; and R ₄ to R ₈ are the same or different and each represents a carbon number of 1 to 1; The alkyl group of 3 or the alkyl group containing a halogen, and X is the same or different, and represents a hydrogen atom, an alkyl group having 1 to 3 carbon atoms or an alkoxy group having 1 to 3 carbon atoms, and n is 14).

In the polymerization, the repeating unit is usually dissolved in a solvent, a catalyst is added, and polymerization is carried out while heating or cooling. The polymerization reaction depends on the type of the initiator, the initiation method of heat or light, the polymerization conditions of temperature, pressure, concentration, solvent, additives, and the like. In the polymerization of the functional resin composition of the present invention, radical polymerization using a radical generator such as azoisobutyronitrile or ion polymerization using a catalyst such as alkyllithium or the like is usually used. The method can be carried out in accordance with a usual method.

In the present invention, the following materials can be mentioned as a raw material copolymerized with the compound represented by the formula (1). 2-methyl-2-adamantyl (meth) acrylate, 2-ethyl-2-adamantyl (meth) acrylate, 2-(meth) propylene oxy-2- (1-adamantyl)propane, 2-(methyl)propenyloxy-2-(1-adamantyl)butane, 3-(methyl)propenyloxy-3-(1-adamantane Adamantane, 3-hydroxy-1-adamantyl (meth) acrylate, adamantyl acrylate derivative such as 3,5-dihydroxy-1-adamantyl (meth) acrylate, hydroxyl group Styrene, α-methylstyrene, 4-tert-butoxystyrene, 4-tert-butoxycarbenyl styrene, 4-tert-butoxycarbenylmethoxystyrene, 4 a hydroxystyrene derivative such as -(2-t-butoxycarbenylethoxy)styrene, a third butyl (meth)acrylate, an isodecyl (meth)acrylate, or a (meth)acrylic acid Cyclodecyl ester, β-(meth) propylene methoxy γ-butyrolactone, β-(meth) propylene decyloxy β-methyl-γ-butyrolactone, α-(meth) propylene oxime Oxy-γ-butyrolactone, α-(meth)propenyloxy α-methyl-γ-butyrolactone, α-(methyl)propenyloxy γ, γ-dimethyl-γ-butyl Lactone, 5-(meth)acryloxy 3-oxy-3 Ring [4.2.1.0 ^4.8 ] decan-2-one (=9-(methyl)propenyloxy 2-oxatricyclo[4.2.1.0 ^4.8 ]nonan-3-one), 6-(methyl Acryloxy 3-oxatricyclo[4.3.1.1 ^4.8 ]undec-2-one), 2-methyl-2-(methyl)propenyloxycyclopentane, 2-ethyl- 2-(Methyl)acryloxycarbonylcyclopentane or the like. Other repeating units may be used alone or in combination of two or more.

The polymer of the present invention is preferably converted into a polystyrene weight average molecular weight (hereinafter referred to as "Mw") by a gel permeation chromatography (GPC) of preferably 1,000 to 150,000, more preferably 3,000 to 100,000. Further, the ratio (Mw/Mn) of the Mw of the polymer to the number average molecular weight (hereinafter referred to as "Mn") in terms of polystyrene measured by GPC is usually from 1 to 10, preferably from 1 to 5. In the present invention, the polymer may be used singly or in combination of two or more.

The functional resin composition of the present invention contains the above polymer and a photoacid generator in a solvent. The resin solvent to be used, for example, is a linear ketone such as 2-pentanone or 2-hexanone, a cyclic ketone such as cyclopentanone or cyclohexanone, or propylene glycol monomethyl ether acetate. Ethylene glycol monoalkyl ether acetate such as propylene glycol monoalkyl ether acetate such as propylene glycol monoethyl ether acetate, ethylene glycol monomethyl ether acetate or ethylene glycol monoethyl ether acetate a propylene glycol monoalkyl ether such as an ester, propylene glycol monomethyl ether or propylene glycol monoethyl ether; ethylene glycol monoalkyl ether such as ethylene glycol monomethyl ether or ethylene glycol monoethyl ether; An ester of diethylene glycol dialkyl ether such as ethylene glycol dimethyl ether or diethylene glycol diethyl ether, ethyl acetate or ethyl lactate, cyclohexanol or 1-octyl An alcohol such as an alcohol, ethylene carbonate, γ-butyrolactone or the like. These solvents may be used singly or in combination of two or more.

The photoacid generator can be appropriately selected from the range of the thickness of the photoresist coating film and the light absorption coefficient of the photoresist generator in accordance with the exposure wavelength and the acid generator which can be used as the chemically amplified photoresist composition. The photoacid generator may be used singly or in combination of two or more. The photoacid generator is used in an amount of preferably 0.1 to 20 parts by weight, more preferably 0.5 to 15 parts by weight per 100 parts by weight of the resin.

Examples of the photoacid generator that can be used include an onium salt compound, a sulfonium imide compound, an anthraquinone compound, a sulfonate compound, a quinonediazide compound, and a diazomethane compound. An onium salt compound such as a phosphonium salt, an iodonium salt, a phosphonium salt, a diazonium salt or a pyridinium salt is preferred.

As for KrF excimer laser (wavelength 248 nm) or ArF excimer laser (wavelength 193 nm), F ₂ excimer laser (wavelength 157 nm), extreme ultraviolet (wavelength 13 nm), X-ray And an electron beam or the like, which can be suitably used as a photoacid generator, and specifically, triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium hexafluoroantimonate, triphenylsulfonium naphthalenesulfonate, Hydroxyphenyl)benzylbenzylmethylindole sulfonate, diphenyliodonium trifluoromethanesulfonate, diphenyliodonium sulfonate, diphenyliodonium dodecylbenzenesulfonic acid Salt, diphenyl iodonium hexafluoroantimonate, and the like.

An acid diffusion controlling agent can be provided which has a function of controlling the diffusion of an acid generated from the acid generator by the exposure agent in the photoresist film and suppressing a chemical reaction which is not preferred in the non-exposed area. As the acid diffusion controlling agent, a nitrogen-containing organic compound whose alkalinity does not change due to exposure or heat treatment in the photoresist pattern forming process is preferable. Examples of such a nitrogen-containing organic compound include a monoalkylamine such as n-hexylamine, n-heptylamine or n-octylamine; a dialkylamine such as di-n-butylamine; and a trialkyl group such as triethylamine. Amines; aromatic amines such as aniline, N,N-dimethylaniline, 2-methylaniline, 3-methylaniline, 4-methylaniline, 4-nitroaniline, diphenylamine, etc.; An amine compound such as an amine, a guanamine compound such as carbamide, N,N-dimethylformamide, N,N-dimethylacetamide or N-methylpyrrolidone, or a urea compound such as urea Examples include imidazoles such as imidazole and benzimidazole; pyridines such as pyridine and 4-methylpyridine; and 1,4-diazabicyclo[2.2.2]octane. The amount of the acid diffusion controlling agent is usually 15 parts by weight or less per 100 parts by weight of the resin, more preferably 0.001 to 10 parts by weight, still more preferably 0.005 to 5 parts by weight.

Further, the functional resin composition of the present invention may contain various additives such as a surfactant, a quencher, a sensitizer, and an antihalation which are also used in the prior chemically amplified photoresist composition as necessary. Various additives such as agents, preservation stabilizers, and defoamers. Examples of preferred sensitizers include oxazoles, diphenyl ketones, rosin, and anthraquinones.

Examples of the surfactant which can be used include a nonionic surfactant such as polyoxyethylene lauryl ether or polyethylene glycol dilauryl ester, and a surfactant which is sold under the following brand name, MEGAFAC F173 (large Nippon Ink Chemical Industry Co., Ltd., L-70001 (manufactured by Shin-Etsu Chemical Co., Ltd.), EFTOP EF301, EF303, EF352 (manufactured by TO-Chemproducts), Furorad FC430, FC431 (manufactured by Sumitomo 3M), ASAHI GUARD AG710, SURFLON S-382, SC101 , SC102, SC103, SC104, SC105, SC106 (made by Asahi Glass Co., Ltd.), KP341 (made by Shin-Etsu Chemical Co., Ltd.), POLYFLOW No. 75, No. 95 (manufactured by Kyoeisha Chemical Co., Ltd.).

When the resist pattern is formed from the resin composition of the present invention, the composition solution prepared as described above can be applied to a tantalum wafer, for example, by a suitable coating means such as a spin coater, a dip coater or a roll coater. A photoresist film is formed on a substrate such as metal, plastic, glass, or ceramic, and is heat-treated at a temperature of about 50 to 200 ° C in advance, and then exposed through a predetermined mask pattern. The thickness of the coating film is, for example, 0.01 to 20 μm, preferably about 0.02 to 1 μm. The exposure can utilize light of various wavelengths, such as ultraviolet rays, X-rays, etc., for example, suitably using F ₂ excimer laser (wavelength 157 nm), ArF excimer laser (wavelength 193 nm) or KrF excimer laser Far ultraviolet rays such as (wavelength 248 nm), extreme ultraviolet rays (wavelength 13 nm), X-rays, electron beams, and the like are used as light sources. In addition, the exposure conditions such as the amount of exposure can be appropriately selected in accordance with the blending composition of the functional resin composition and the type of each additive.

In the present invention, in order to stably form a fine pattern having high precision, it is preferable to carry out heat treatment at a temperature of 50 to 200 ° C for 30 seconds or more after exposure. At this time, when the temperature is less than 50 ° C, there is a possibility that the variation in sensitivity may increase depending on the type of the substrate. Subsequently, a predetermined photoresist pattern is formed by using an alkaline developing solution, usually at 10 to 50 ° C for 10 to 200 seconds, preferably 20 to 25 ° C, for 15 to 90 seconds.

As the alkaline developing solution, for example, an alkali metal hydroxide, an aqueous ammonia, an alkylamine, an alkanolamine, a heterocyclic amine, a tetraalkylammonium hydroxide, or a choline can be used. a basic compound such as 8-diazabicyclo-[5.4.0]-7-undecene or 1,5-diazabicyclo-[4.3.0]-5-nonene, usually 1 to 1 An alkaline aqueous solution obtained by dissolving at a concentration of 10% by weight, preferably 1 to 3% by weight. Further, a water-soluble organic solvent or a surfactant may be added as appropriate to the developing solution composed of the above alkaline aqueous solution.

Example

Hereinafter, the present invention will be specifically described by way of examples. However, the present invention is not completely limited to the embodiments.

Example 1

In a flask equipped with a stirrer, a thermometer, a dropping funnel, and a Dimroth condenser, 100 g of 1,3-adamantanediol, 1200 g of 96% by weight of concentrated sulfuric acid were added, and dropped into 50 in 1 hour. Formic acid was then allowed to react at 25 ° C for 10 hours. The reaction solution was crystallized when it was added in a small amount to 2000 g of ice-cold water each time. When the precipitated crystals were suction-filtered using a glass funnel, 113 g of 1,3-adamantane dicarboxylic acid was obtained.

In a flask equipped with a stirrer, a thermometer, and a dimro reflux condenser, 100 g of 1,3-adamantane dicarboxylic acid, 200 g of methanol, and 20 g of concentrated sulfuric acid were added, and heated at 60 ° C for 4 hours. After the reaction solution was cooled, 300 ml of ion-exchanged water was added, and then 300 ml of toluene and 300 ml of ethyl acetate were added and transferred to a separatory funnel to carry out liquid separation. Further, 300 ml of toluene and 300 ml of ethyl acetate were added to the aqueous layer and liquid separation was carried out twice. The toluene/ethyl acetate layer was washed with 200 g of a 5% by weight aqueous sodium hydroxide solution and 200 ml of ion-exchanged water, and then concentrated to give 91 g of dimethyl 1,3-adamantane dicarboxylate.

In a flask equipped with a stirrer, a thermometer, a dropping funnel, and a Dimro reflux condenser, 150 g of 1,3-adamantane dicarboxylate and 750 ml of tetrahydrofuran solution were added, and the mixture was dropped into 1308 at 10 ° C for 4 hours. ML 3M methylmagnesium chloride-tetrahydrofuran solution. After the completion of the dropwise addition, the mixture was stirred at room temperature for 15 hours. Subsequently, the flask was ice-cold and neutralized using 700 g of a 10% by weight aqueous sulfuric acid solution. The reaction solution was separated into an organic layer and an aqueous layer, and the organic layer was washed twice with 500 ml of ion-exchanged water, and then concentrated. The obtained crude product was purified using a silica gel column chromatography to give 90 g of methyl 3-(1-hydroxy-1-methylethyl) adamantane-1-carboxylate.

In a flask equipped with a stirrer, a thermometer, and a rectifying tube, 90 g of methyl 3-(1-hydroxy-1-methylethyl)adamantane-1-carboxylate, 43.2 g of potassium t-butoxide, and 450 ml of the flask were added. Tributyl alcohol and 450 ml of toluene were heated to 85 ° C in an oil bath, and the produced methanol was passed through a rectification tube simultaneously with a third butanol and toluene, and the mixture was slowly distilled off and allowed to react for 20 hours.

After the reaction, the reaction solution was ice-cooled, and 1000 ml of a 10% by weight aqueous solution of ammonium chloride and 1800 ml of toluene were added and stirred, and the organic layer and the aqueous layer were separated. Further, the organic layer was washed twice with 1000 ml of ion-exchanged water. The organic layer was concentrated and purified using a silica gel column chromatography to give 57 g of 3-(1-hydroxy-1-methylethyl) adamantane-1-carboxylic acid tert-butyl ester. The obtained white solid was identified by ¹ H-NMR (see Fig. 1).

In a flask equipped with a stirrer, a thermometer, a dropping funnel, and a Dimro reflux condenser, 50 g of 3-(1-hydroxy-1-methylethyl)adamantane-1-carboxylic acid tert-butyl ester, 200 ml was added. Dichloroethane and 80 g of pyridine were added dropwise to 71.7 g of methacrylic acid chloride at 60 ° C for 2 hours. After completion of the dropwise addition, the mixture was further stirred at 60 ° C for 8 hours. Subsequently, the flask was ice-cold and neutralized using 320 g of a 10% aqueous sulfuric acid solution. The reaction solution was separated into an organic layer and an aqueous layer, and the organic layer was washed twice with 500 ml of ion-exchanged water, and then concentrated. The obtained crude product was purified by silica gel chromatography to give 25 g of 3-(1-methylpropenyloxy-1-methylethyl)adamantane-1-carboxylic acid as a white solid. Butyl ester. The obtained white solid was identified by ¹ H-NMR (see Figures 2, 3 and 4).

Fig. 1 shows ¹ H-NMR, 500 MHz, and heavy chloroform of a white solid of Example 1.

Fig. 2 shows ¹ H-NMR, 500 MHz, and heavy chloroform of the white solid 2 of Example 1.

Fig. 3 shows ¹³ C-NMR, 500 MHz, heavy chloroform of the white solid 2 of Example 1.

Figure 4 is a graph showing the IR of the white solid 2 of Example 1.

Claims (5)

An adamantane derivative represented by the following formula (1), (wherein R ₁ to R ₃ are the same or different and each represents a hydrogen atom, an alkyl group having 1 to 3 carbon atoms or an alkyl group containing a halogen; and R ₄ to R ₈ are the same or different and are represented by a carbon number of 1 to 3; The alkyl group or the halogen-containing alkyl group, X is the same or different, and is represented by a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, and n is 14). The adamantane derivative of claim 1, wherein R ₁ and R ₂ are a hydrogen atom, R ₃ is a hydrogen atom or a methyl group, R ₄ to R ₈ are a methyl group or an ethyl group, and X is a hydrogen atom. a polymer containing a repeating unit represented by the following formula (2), (wherein R ₁ to R ₃ are the same or different and each represents a hydrogen atom, an alkyl group having 1 to 3 carbon atoms or an alkyl group containing a halogen; and R ₄ to R ₈ are the same or different and are represented by a carbon number of 1 to 3; The alkyl group or the halogen-containing alkyl group, X is the same or different and is represented by a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, and n is 14). A resin composition for photoresist, which is contained in the third of the patent application scope The polymer of the item. A method for producing an adamantane derivative represented by the formula (1) according to the first aspect of the invention, which comprises the adamantyl alcohol represented by the following formula (8) and represented by the following formula (9) or (10) Acrylic compound reaction, (wherein R ₄ to R ₈ are the same or different, and are represented by an alkyl group having 1 to 3 carbon atoms or an alkyl group containing a halogen, and X is the same or different and is represented by a hydrogen atom or an alkyl group having 1 to 3 carbon atoms; Alkoxy group having 1 to 3 carbon atoms, and n is 14) (R ₁ to R ₃ are the same or different and each represents a hydrogen atom, an alkyl group having 1 to 3 carbon atoms or an alkyl group containing a halogen, and Z is a hydroxyl group, an alkoxy group or a halogen group) (wherein R ₁ to R ₃ are the same or different and each represents a hydrogen atom, an alkyl group having 1 to 3 carbon atoms or an alkyl group having a halogen atom or a halogen group).